Create reverse-string.cpp

Author: kamyu104

C++/reverse-string.cpp

@@ -0,0 +1,22 @@
+// Time:  O(n)
+// Space: O(1)
+
+class Solution {
+public:
+    string reverseString(string s) {
+        for (int i = 0, j = s.length() - 1; i < j; ++i, --j) {
+            swap(s[i], s[j]);
+        }
+        return s;
+    }
+};
+
+// Time:  O(n)
+// Space: O(1)
+class Solution2 {
+public:
+    string reverseString(string s) {
+        reverse(s.begin(), s.end());
+        return s;
+    }
+};